The present invention relates generally to a modular hand guard assembly for firearms. More specifically, the present invention relates to a modular assembly that is affixed to a firearm that facilitates integration and mounting of additional equipment onto a firearm.
In the general field of combat and commercial weaponry, numerous add-on enhancements have become available for attachment to standard firearms thereby significantly upgrading the capability of the firearm. One area within the broad scope of available firearms that is of particular interest is the M16/M4 weapon system typically utilized in military or law enforcement settings. Referring to FIG. 1, the M16/M4 weapon, generally indicated at 2, includes a lower receiver 3, an upper receiver 4, a butt stock 5 extending rearwardly from the upper and lower receivers 3,4, and a barrel 6 that is attached to the front of the upper receiver 4 and extends in a forward direction. The barrel 6 is held in position on the front of the upper receiver 4 by a barrel nut 7 (See FIG. 8) that is threaded onto a threaded barrel receiving receptacle (not shown) located on the front of the upper receiver 4. Most new models of the M16/M4 weapons also include a dovetail interface rail 8 integrally formed along the top of the upper receiver 4. This interface rail 8 provides a convenient mounting point for many of the available accessories for use with the M16/M4 firearm 2 such as scopes, sighting devices, lasers and directed fire devices. Since this interface rail 8 extends only along the upper receiver 4 the interface is limited in length to the length of the receiver 4. The difficulty is that many end users of this weapon system have multiple sighting devices in addition to a variety of lighting devices, accessory handgrips, etc. that are selectively attached to the weapon 2 for enhanced use of the weapon. Generally, there is not enough space on the interface rail 8 of the upper receiver 4 to accommodate all of the accessories that the user may desire to use.
In an attempt to overcome the space limitations, various methods and means have been developed for interchangeably attaching add-on enhancements to firearms. For example, U.S. Pat. No. 4,845,871 discloses a quickly detachable mounting interface for modular enhancements. Similarly, U.S. Pat. No. 5,142,806 discloses a universal receiver sleeve that increases the available rail space. More specifically, the sleeve has an extended upper interface rail with standard, universal dimensions regardless of the firearm and has a lower interface portion specific to a particular firearm. Another interface system is disclosed in U.S. Pat. No. 5,343,650 where an extended rigid interface frame is joined to a firearm receiver and extends forward about the firearm's barrel to a head assembly replacing the firearm's normal front sight. The distal end of the extended rigid frame receiver sleeve terminates in a front sight housing, which provides a housing for advanced laser and sensor components, and the standard front sight bead.
One of the continuing drawbacks of the prior art mounting systems is that they still do not provide enough room along the interface rails to allow multiple accessories to be used in conjunction with one another. Often, since one of the primary accessories used on the upper rail is an optical sight, most other accessories can't be mounted on the upper rail forward of the sight, because they end up blocking the sight. Further, as many of these devices are selectively moved onto and off of the upper rail, it is important that they can be replaced with a high degree of predictability with respect to their alignment (ability to repeat zero).
Accordingly, there is a clear need for an integration system that includes additional mounting interfaces for accessories that reduces interference with other accessories already residing on the upper rail mount. There is a further need of a modular hand guard assembly that provides an easily removed section that allows mounting of an accessory on the forward portion of the hand guard that positions the accessory out of the way of the various sighting devices already positioned on the upper rail. There is still a further need for a modular and integrated switching and control system for activating various electronic weapon accessories from a common location.